1. Field of the Invention
The present invention relates to a method and system for tracking and managing a patient's compliance with a medical treatment regimen or prescription, and, in particular, to a method and system that tracks and manages a patient's compliance with a prescribed usage of a medical device.
2. Description of the Related Art
It is well known to treat a medical disorder or to diagnose, treat or monitor the condition of a patient using medical equipment. For example, patients suffering from a pulmonary or respiratory disorder, such as obstructive sleep apnea (OSA), are often treated with a pressure support device, such as a continuous positive airway pressure (CPAP) device. A CPAP device delivers a flow of fluid to the airway of the patient throughout the patient's breathing cycle in order to “splint” the airway, thereby preventing its collapse during sleep. Examples of such CPAP devices are the REMstar® and Solo® family of CPAP devices manufactured by Respironics, Inc. of Pittsburgh, Pa.
It is also known to provide a bi-level positive pressure therapy, in which the pressure of fluid delivered to the patient's airway varies or is synchronized with the patient's breathing cycle to maximize the medical effect and comfort to the patient. An example of pressure support devices that provide “bi-level” pressure support, in which a lower pressure is delivered to that patient during the patient's expiratory phase than during the inspiratory phase, is the BiPAP® family of devices manufactured and distributed by Respironics, Inc. of Pittsburgh, Pa. Such a bi-level mode of pressure support is taught, for example, in U.S. Pat. No. 5,148,802 to Sanders et al.; U.S. Pat. No.5,313,937 to Zdrojkowski et al.; U.S. Pat. No. 5,433,193 to Sanders et al.; U.S. Pat. No. 5,632,269 to Zdrojkowski et al.; U.S. Pat. No.5,803,065 to Zdrojkowski et al.; and U.S. Pat. No. 6,029,664 to Zdrojkowski et al., the contents of each of which are incorporated by reference into the present invention.
It is further known to provide an auto-titration positive pressure therapy in which the pressure provided to the patient changes based on the detected conditions of the patient, such as whether the patient is snoring or experiencing an apnea, hypopnea, or upper airway resistance. An example of a device that adjusts the pressure delivered to the patient, based on whether or not the patient is snoring, is the Virtuoso® CPAP family of devices manufactured and distributed by Respironics, Inc. An example of a pressure support device that actively tests the patient's airway to determine whether obstruction, complete or partial, could occur and adjusts the pressure output to avoid this result is the Tranquility® Auto CPAP device, also manufactured and distributed by Respironics, Inc. An exemplary auto-titration pressure support mode is taught, for example, in U.S. Pat. Nos. 5,203,343; 5,458,137; and 6,087,747, all to Axe et al., the contents of which are incorporated herein by reference. A further example of an auto-titration pressure support device that actively tests the patient's airway to determine whether obstruction, complete or partial, could occur and adjusts the pressure output to avoid this result is the Tranquility® Auto CPAP device, also manufactured by Respironics, Inc. This auto-titration pressure support mode is taught in U.S. Pat. No. 5,645,053 to Remmers et al., the content of which is also incorporated herein by reference.
In treating a patient using any of the above-described pressure support systems, each of which represents a mode of providing pressure support, it is often desirable to monitor various parameters associated with the use of such systems. Once a patient is diagnosed with a breathing disorder, he or she is typically prescribed a pressure support therapy, i.e., a mode of pressure support (CPAP, bi-level, or auto-titration) and given a prescribed pressure support level. The pressure support therapy (mode of pressure support and pressure settings) is typically prescribed by a physician after the patient undergoes a sleep study at a sleep lab. The patient's healthcare provider, such as that patient's physician or health insurance company, is often interested in ensuring that the patient actually uses the pressure support therapy as prescribed. Thus, it is known to monitor a patient's compliance with the prescribed therapy by monitoring the patient's usage of the pressure support device.
Typically, a doctor or other health care provider is able to track and monitor a patient's compliance with the prescribed pressure support device usage by tracking the operation of the prescribed pressure support device. In addition, a status monitor may be in communication with the respiratory apparatus that delivers breathable gas to the airway of a patient. The status monitor determines the status of the usage of the unit by the patient and includes a timer for determining the accumulated time of usage of the unit by the patient. See, e.g., U.S. Pat. No. 5,517,983 to Deighan et al. As shown in U.S. Pat. No. 5,706,801 to Remes et al., such compliance monitors also may have remote communication functionality, allowing the usage information to be transmitted from the device to a remote computer.
However, these conventional compliance monitoring systems are deficient in that they measure only the operational or device usage time, whether through device operation, cannula operation, air flow measurement, etc. These devices then provide a total usage time, from which the device or a remote computer calculates the compliance with the prescribed total usage time. The measurement and compliance monitoring is a strictly static one and only provides limited “snap shots” demonstrating compliant or non-compliant behavior. Therefore, there remains a need for a method and system for dynamically tracking and monitoring a patient's compliance with a prescribed device usage allotment during a cycle of predetermined periods.
Another deficiency evident in the conventional compliance monitoring methods and systems stems from their definition of “compliance.” In other words, these systems track, monitor, and manage a “technical” compliance level for a patient. For example, if a patient is prescribed a device usage time of eight hours of usage in a 24-hour period, the mere fact that the patient uses the device for 8 hours during that period does not necessarily indicate that the patient is “compliant.” In prior art systems, any usage of the device is accrued towards the prescription level.
However, relatively short usage sessions, e.g., sessions where the medical device is used continuously for ten or twenty-minutes or less, may not effectively treat the patient. This is because a person with normal sleeping patterns will go through a cycle of different stages of sleep during the course of a night. The cycle for a particular person is a sequence of these stages, usually in the same order, with a relatively constant time in each stage. Any disruption causes this normal pattern to be disturbed, resulting in a reduction of time in each stage of sleep, which can have negative effects on health. Short sessions indicate that the patient is waking frequently and thus creating this disruption of normal sleep patterns. Therefore, there remains a need for a compliance method and system that ensures that the patient is meeting an actual compliance level, as opposed to a “technical” compliance level.